From: Martin Durai <martin@...>
Date: 2007-11-22T17:59:19+09:00
Subject: Re: read, write, seek method in a ring buffer class

Actually i need to create a ring buffer class, with read, write, seek 
methods.

Read should take number as an argument(number of bytes to read) and 
should return a string. when you read, you need to read either the 
request number of bytes or the availlable number of bytes, whichever is 
smaller. when you read you advance forward the read_position.

similarly write method should take string as a argument. now advance 
forward the write position.

seek should take number as a argument and return nothing. it should do 
range checking. seek changes the read position.

I have attached my code with this mail please make necessary changes in 
it and also help me to code seek method.

Thanks in advance

 class RingBuffer

  # Instanciate a ring buffer of the given size.
  # The buffer will contain at most +size+ elements

  def initialize(size)

    # initialize the maximum

    @max = size

    #Initialize the buffer

    @buffer = Array.new

  end

  #
  # method call to read contents from the buffer
  #


  def read(number_of_bytes)
  #------------------------------------

    # initialize the buffer size

    buffer_size=@buffer.length

    # is number of bytes greater than buffer size

    if number_of_bytes < buffer_size

      # if so

      # initialize the new buffer array

      @newBuffer = Array.new

      # initialize new buffer

      @newBuffer = @buffer[0..number_of_bytes]

      # return all elements in buffer as string

      @newBuffer.each() { |block|
                                    return block.to_s}

      #if not

      else

        # initialize the newbuffer array

        @newBuffer = Array.new

        # initialize the now buffer

        @newBuffer = @buffer[0..buffer_size]

        # return all the elements in buffer as string

        @newBuffer.each() { |block| puts block.to_s}

      end

    end

    #
    # method call to write contents in the buffer
    #
      def write(string_value)
    #-----------------------------

      #initialize the buffer size

      buffer_size=@buffer.length

      # is buffer size is greater than maximum

      if buffer_size > @max

        # if so
        # remove the first element in the buffer

        @buffer.shift

        # if not

        else

          # write  a element to the buffer

          @buffer << string_value

      end

    end


    def seek

    end


  end




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